and M. Volpicelli concluded the work of the section by a communication on Electrostatic Induction.

Geology is the branch of Natural History which is most cultivated in Switzerland. Notwithstanding its small extent, that country has the most varied field for observation in the mountain-chains of the Jura and the Alps; there are few important questions whose solution cannot be found in these mountains; and many Swiss names are found among those who have done most to advance that science. During the last year geological studies have received a great impulse in Switzerland by the subsidies which the Confederation vote for that purpose; each year the State grants a sum in aid of the researches of a certain number of geologists, and for the study of a new part of the territory. The works which result are published under the care of a special commissioner of the Society of Natural Science. As might be expected then, the Geological Section was very numerously attended, and the papers read on the subject were many and valuable. We learn from M. A. Fauzes' general lecture that the Society have taken similar steps for the study and preservation of Swiss boulders to those taken by the Royal Society of Scotland, whose report we gave in a recent number.

M. V. Gross brought under the notice of the members a series of objects belonging to the lacustrine, dwellings of the Lake of Bienne, worthy of the attention even of those who have seen the richest collections of this kind. There was the bit of a bridle almost complete belonging to the station of Mörigen, which belongs to the age of bronze; at the present time only one similar fragment is known. Incrustations of iron upon a bronze knife tend to confirm what has already been conjectured, that at the first appearance of iron it was regarded as a most precious metal. The station of Lüschersz, of the stone age, has been discovered by M. Gross, and has furnished axes of nephrite and jade of a size not hitherto met with in lacustrine dwellings. It is known that these rocks are not found in Europe; and it is a question whether these lake-dwellers obtained them by commercial intercourse with Asia, or whether these rare articles were preserved as heirlooms in families from the period of their emigration from their ancient Asiatic home.

M. Ch. Vogt communicated to the section the results of his microscopic study of rocks. One of the questions which he wished to resolve is whether the microscope can enable us to know whether or not a rock has ever been in an igneous state. M. Vogelsang has discovered that the volcanic rocks present what has been called the "fluidal structure," a structure resulting from the disposition of minute crystals disseminated throughout the vitreous mass, and surrounding the larger crystals which have been previously formed in the lava. This fluidal structure is found in the porphyries, and proves their igneous origin. But on examining the siliceous deposits of the Geyser, M.Vogt found this same structure, and thus it does not belong exclusively to the igneous rocks, but also to those of aqueous origin, provided that they have been in a viscous state. In his study of volcanic rocks, M. Vogt has discovered that the trachytes, the basalts, and the lavas, present common characteristics.

M. Lebert brought under the notice of the section a magnificent series of specimens of amber, and expounded the results of his researches on that substance. The fluorescence of petroleum may be taken as a type of the same phenomenon in amber. For naturalists the most interesting of M. Lebert's specimens are fragments of the conifers which produced the amber, a piece enclosing a movable air-bubble in a drop of water, and a great number of other pieces enclosing insects in a perfect state of preservation.

M. François Forel exhibited a photograph of the fossil man of Mentone, which represents him in the position in which he was found. It would appear that this man was

not buried under a landslip, but that he must have been interred by those who survived him. It is argued that, because it is very unusual to inter the dead in a dwelling for the living, we may conclude that this individual be longed to a nomad horde of the age of the reindeer, who did not inhabit the cavern, but passed it from time to time, and who buried this man in the place where he died. We may mention here that in the Zoological section Dr. Vonga read a paper on the same subject, he having been present at the exhumation of the body. He described the caves, and pointed out their probable mode of formation. The body lay upon its left side in the posi tion of sleep. It showed a circular crack at the base of the skull, the thorax being broken at one place; the remainder is in perfect preservation. The cranium is very fine, all the teeth being preserved; the lower jaw is long, but the angle between the horizontal and the ascending branches is a right angle. Dr. Vonga attributed the remarkable preservation of the body to the properties of the pulverised earth which covered it.

Several members presented to the section their studies of various parts of the Alps, and M. E. Favre read a paper on a section of the Caucasus. In the centre of the latter chain a granitic formation is found. On the two sides paleozoic schists are presented, analogous to those of Grätz, and connected by veins of crystalline schist. They are less developed on the north side than on the other. Upon the northern slope the Secondary and Tertiary formations are in a very normal position, and have but little inclination; upon the other slope, on the contrary, there are many zones of eruptive rocks, and the Secondary formations are less disturbed. M. Favre also spoke to the section on the lower limit of eternal snow and the glacial phenomena which he has observed in this chain.

In the section of Zoology Prof. C. Vogt presented the results of his researches upon the Phyllopodes, especially the Branchiopods and the Artemia.

M. Vogt confirmed the observation of M. Joly, that among the Artemia collected at Cette during the months of July and August, no males were found, and that the females reproduced by parthenogenesis. This fact is so much the more singular that large numbers of males are found in other salt marshes inhabited by the same or analogous species.

M. Auguste Forel presented to the section some curious and interesting results of his researches into the nature and habits of ants. Different communities of ants, even when they are of the same species, are enemies to each other. A single community of ants may possess many nests, which are connected with each other by galleries and tunnels. A community of ants may be either simple or mixed; it is simple when it belongs to a single species, mixed when it belongs to two or more species living on good terms among themselves. There are in each com munity, at one time at least, workers, some males and females. If we consider the mixed communities, we can distinguish, amongst others, slave-ants, obtained by the workers of one species pillaging the ant-hills of another species, and carrying off the cocoons. These, when once hatched, become the auxiliary workers and friends of their captors, doubtless believing that they are of the same origin. The mixed community contains the three sexes of the species who plundered, but only the workers of the species pillaged.

The only paper apparently of importance in the Botanical Section was by Dr. Müller, of Geneva, on a new species of Loranthus from the Philippine Islands, which, from the position of the flowers, presents some very extraordinary but not yet well-established peculiarities.

Other papers of value were read in the various sections, and, considering that the meeting lasted only three days, the amount of work gone through appears extraordinary; but then no mention is made of any excursions.

The blind fish of the Wyandotte Cave is the same as that of the Mammoth, the Amblyopsis spelaus DeKay. It must have considerable subterranean distribution, as it has undoubtedly been drawn up from four wells in the neighbourhood of the cave. Indeed, it was from one of these, which derives its water from the cave, that we procured our specimens. We descended a well to the water, some twenty feet below the surface, and found it to communicate by a side opening with a long low channel, through which flowed a lively stream of very cold water. Wading up the current in a stooping posture, we soon reached a shallow expansion or pool. Here a blind crawfish was detected crawling round the margin, and was promptly consigned to the alcohol bottle. A little farther beyond, deeper water was reached, and an erect position became possible. We drew the seine in a narrow channel, and after an exploration under the bordering rocks, secured two fishes. A second haul secured another. Another was seen, but we failed to catch it, and on emerging from the cave I had a fifth securely in my hand, as I thought, but found my fingers too numb to prevent its freeing itself by its active struggles.

If these Amblyopses be not alarmed, they come to the surface to feed, and swim in full sight like white aquatic ghosts. They are then easily taken by the hand or net, if perfect silence is preserved, for they are unconscious of the presence of an enemy except through the medium of hearing. This sense is, however, evidently very acute, for at any noise they turn suddenly downward and hide beneath stones, &c., on the bottom. They must take much of their food near the surface, as the life of the depths is apparently very sparse. This habit is rendered easy by the structure of the fish, for the mouth is directed partly upwards, and the head is very flat above, thus allowing the mouth to be at the surface. It thus takes food with less difficulty than other surface feeders, as the perch, &c., where the mouth is terminal or even inferior; for these require a definite effort to elevate the mouth to the object floating on the surface. This could rarely be done with accuracy by a fish with defective or atrophied visual organs. It is therefore probable that fishes of the type of

the Cyprinodontida, the nearest allies of the Hypsarida, and such Hypside as the eyed Chologaster, would possess in the position of the mouth a slight advantage in the struggle for existence.

The blind crawfish above mentioned is specifically distinct from that of the Mammoth Cave, though nearly related to it. I call it Orconectes inermis, separating it generically from Cambarus, or the true crawfishes, on account of the absence of visual organs. The genus Orconectes, then, is established to include the blind crawfishes of the Mammoth and Wyandotte Caves.

Dr. Packard has described an interesting genus of Isopoda allied to the marine form Idotea, which Mr. Cooke discovered in a pool in the Mammoth Cave. He called it Cæcidotea. I obtained a second species in a cave adjoining the Wyandotte which differs in several important respects. I call it Cæcidotea microcephala. Both species are blind. The new species is pure white. It was quite active, and the females carried a pair of egg-pouches full of eggs. The situation in which we found it was peculiar. It was only seen in and near an empty log trough used to collect water from a spring dripping from the roof of one of the chambers.

The Lernaan, Cauloxenus stygius Cope, is a remarkable creature. It is a parasite on the blind fish, precisely as numerous species near of kin attach themselves to various species of marine fishes. The Wyandotte species is not so very unlike some of these. It is attached by a pair of altered fore-limbs, which are plunged into the skin of the host, and held securely in that position by the barbed or recurved claws. No parasitic male was observed in the neighbourhood of the female, and it is probable that, as in the other Lernæopodide, he is a free swimmer, and extremely small. The difficulty of finding his mate on an active host-fish must be augmented by the total darkness of his abode, and many must be isolated owing to the infrequent and irregular occurrence of the fish, to say nothing of the scarceness of its own species.

The allied genera, Achtheres and Lernæopoda, present very distinct distributions, the former being fresh water and the latter marine. Lernæopoda is found in the most varied types of fishes and in several seas; Achtheres has been observed on perch from Asia and Europe, and on a South American Pimelodus. It is to the latter that Cauloxenus is most nearly allied, and from such a form we may, perbaps, trace its descent; modification being consequent on its wandering into subterranean streams. The character which distinguishes it from its allies is one which especially adapts it for maintaining a firm hold on its host, i.e., the fusion of its jaw-arms into a single stem.

Whether the present species shared with the Amblyopsis its history and changes, or whether it seized upon the fish as a host at some subsequent period, is a curious speculation. Its location at the mouth of the fish could scarcely be maintained on a species having sight; for if the host did not remove it, other individuals would be apt to.

I may here allude to another blind Crustacean which I took in the Mammoth Cave, and which has been already mentioned in the Annals and Magazine of Natural His tory as a Gammaroid. Mr. Cooke and myself descended a hole, and found, a short distance along a gallery, a clear spring, covering, perhaps, an area ten feet across. Here Mr. Cooke was so fortunate as to procure the Cæcidoten stygia, while I took the species just mentioned, and which I name Stygobromus vitreus. The genus is new, and represents in a measure the Niphargus of Schiödte found in the caves of Southern Europe. This genus has several species in fresh waters, which are of small size, and swin actively, turning on one side or the other.

Of Insects I took four species of beetles, all new to science; two of them of the blind carnivorous genus Anopthhalmus, and two Staphylinida, known by their very short wing-cases and long, flexible abdomen. Dr. George H. Horn has kindly determined them for me.

And another Alæocharyde Staphylinide, allied to Tachyusa, also from Wyandotte Cave. No names have as yet been given to any of these, excepting the second. A monograph of Catops has already appeared containing many species from our fauna; and as the work is inaccessible at present, I have hesitated to do more than indicate the presence of the above species.

The cricket of the Wyandotte Cave is stouter than that of the Mammoth, and thus more like the Raphidophora lapidicola of the forest. There were three species of flies, one or more species of Poduridæ, and a Campodea not determined.

Centipedes are much more abundant in the Wyandotte than in the Mammoth Cave. They especially abounded on the high stalagmites which crown the hill beneath the Mammoth dome, which is three miles from the mouth of the cave. The species is quite distinct from that of the Mammoth Cave, and is the one I described some years ago from caves in Virginia and Tennessee. I call it Spirostrephon cavernarum, agreeing with Dr. Packard that the genus Pseudotremia, to which it was originally referred, is of doubtful validity. The allied form found by Mr. Cooke in the Mammoth Cave has been described by Dr. Packard as Spirostrephon Copei. It is eyeless, and is, on this account alone, worthy of being distinguished generically from Spirostrephon. This genus may be then named Scoterpes. I look for the discovery of S. cavernarum in the Mammoth Cave.

Two species of Arachnidans were observed, one a true spider, the other related to the "long-legs" of the woods. A species similar to the former is found in the Mammoth Cave, and others in other caves, but in every instance where I have obtained them they have been lost by the dissolution of their delicate tissues in the impure alcohol. The other forms are more completely chitinised, and are easily preserved; they are related to the genus Gonyleptes, found under stones in various portions of the country. Dr. Wood describes a species from Texas, and I have taken them in Tennessee and Kansas. In the Wyandotte Cave I found a number of individuals of a new species, at a place called the screw-hole. Though living at a distance of four or five miles from the mouth of the cave, this species is furnished with eyes. This species is described as Erebomaster flavescens Cope. In its relationships it may be said to stand between Acanthocheir and Gonyleptes.

Besides Acanthocheir, another blind Gonyleptid exists in the Mammoth Cave, which I found several miles from the mouth. It is blind like the former, but differs in having many more joints to the tarsi, approaching thus the true Phalangia, or long-legs.

Dr. Packard and Mr. Putnam have already discussed the question of the probability of the origin of these blind cave animals by descent from out-door species having eyes. I have already expressed myself in favour of such view, and deem that in order to prove it we need only

establish two or three propositions. First, that there are eyed genera corresponding closely in other general characters with the blind ones; second, that the condition of the visual organs is in some cave type variable; third, if the abortion of the visual organs can be shown to take place coincidently with general growth to maturity, an important point is gained in explanation of the modus operandi of the process.

First, as to corresponding forms; the Typhlichthys of the Mammoth is identical with Chologaster, except in its lack of eyes. Orconectes bears the same relation to Cambarus; Stygobromus bears nearly the same to Gammarus; and Scoterpes is Spirostrephon without eyes and no pores.

Secondly, as to variability. I have already shown that in Gronias nigrilabris, the blind Silurid from the Conestoga in Pennsylvania, while all of several specimens observed were blind, the degree of atrophy of the visual organs varies materially, not only in different fishes, but on different sides of the same fish. In some the corium is imperforate, in others perforate on one side, in others on both sides, a rudimental cornea being thus present. In some the ball of the eye is oval, and in others collapsed. This fish is related specifically to the Amiurus nebulosus of the same waters, more nearly than the latter is to certain other Amiuri of the Susquehanna river basin to which the Conestoga belongs, as for instance the A. lynx; it may be supposed to have been enclosed in a subterranean lake for a shorter time than the blind fishes of the Western Caves, not only on account of the less degree of loss of visual organs, but also in view of its very dark colours.

Thirdly, it is asserted that the young Orconectes possess eyes, and that perhaps those of the Typhlichthys do also. If these statements be accurate, we have here an example of what is known to occur elsewhere, for instance, in the whalebone whales. In a foetal stage these animals possess rudimentary teeth like other Cetacea, which are subsequently absorbed. This disappearance of the eyes is regarded with reason by Prof. Wyman as evidence of the descent of the blind forms from those with visual organs. I would suggest that the process of reduction illustrates the law of "retardation," accompanied by another phenomenon. Where characters which appear latest in embryonic history are lost, we have simple retardation— that is, the animal in successive generations fails to grow up to the highest point, falling farther and farther back, thus presenting an increasingly slower growth in this special respect. Where, as in the presence of eyes, we have a character early assumed in embryonic life, the retardation presents a somewhat different phase. Each successive generation, it is true, fails to come up to the completeness of its predecessor at maturity, and thus exhibits "retardation;" but this process of reduction of rate of growth is followed by its termination in the part long before growth has ceased in other organs. This is an exaggeration of retardation. Thus the eyes in the Orconectes probably once exhibited at maturity the incomplete characters now found in the young, for a long time a retarded growth continuing to adult age before its termination was gradually withdrawn to earlier stages. Growth ceasing entirely, the phase of atrophy succeeded, the organ became stationary at an early period of general growth, being removed, and its contents transferred to the use of other parts by the activity of "growth force." Thus, for the loss of late assumed organs we have "retardation," but for that of early assumed ones, “retardation and atrophy."

The mutual relations of this cave life form an interesting subject. In the first place, two of the beetles, the crickets, the centipede, the small crustaceans (food of the blind fish) are more or less herbivorous. They furnish food for the spiders, crawfish, Anophthalmus, and the fish. The vegetable food supporting them is in the first place fungi which, in various small forms, grow in damp